he's been telling this joke for more than a year now. I heard it live when I saw him last october. It's not his best joke, but in general he's even more hilarious than ever. At least to me.
As a comic, dave was always pushing the envelope of what's okay to say and not to say. And his humor is very much in the vein of the heteronormative male perspective. the way he delivered it as I heard it was an "I'm a relic of an older time" type of thing. That he can't keep up with this newer age of gender relations and sexual identities, so he feels like a fish out of water. He throws in a disclaimer before he tells the joke that he's "cool with people being whoever they want to be and living their truth, just don't expect him to play along on a personal level," or something to that general effect.
There is without a doubt an edge of transphobia to the joke, and Dave leans into it fully on purpose. He's done it plenty of times for a bunch of other sensitive topics like misogyny, race relations, and homosexuality. I'm not surprised that he offended people: they're purposefully offensive jokes and he utilizes the aura like a prop. If he's been telling that joke for this long, that means it's landing more often than not. And as with the perhaps ulterior reasons people laughed at some of his jokes on the Chappelle Show, this joke's success is most likely an unsavory reflection of the audience who is reacting to it.
There goes the "It's just comedy" defense.
If someone finds it funny they find it funnny. If they don't, they don't. How is it that hard to understand?
You can think things that aren't jokes are funny but that doesn't make them a joke.